Well characterized brains have great utility in studies of HIV neuropathogenesis and studies relating to adequate treatment of viral reservoirs. The Manhattan HIV Brain Bank will utilize pre-extant bank infrastructure located at the Mount Sinai School of Medicine (MSSM), and coordinate patient resources at MSSM, Beth Israel Medical Center (BIMC), and St. Luke's-Roosevelt Hospital Center (SLRHC), three of New York City's largest medical complexes, to: 1. Identify and follow a well- characterized cohort with advanced HIV disease, using neurologic, neuropsychologic, medical, and laboratory examinations; 2. Establish a multi-institutional database in which clinical data are recorded; 3. Obtain autopsy-derived central nervous system (CNS), peripheral nervous system (PNS) and systemic tissues from these patients within 24 hours of their demise; 4. Provide complete pathologic diagnoses of these tissues that will be maintained in a separate but interactive pathology database; 4. Dissect, store, catalogue and distribute these tissues to extramural investigators; 5. Evaluate the appropriateness of tissue requests with a bank review committee that will function under the guidelines of the Network Steering Committee; and 6. Utilize the pathology and clinical databases in correlational studies to elucidate the pathogenesis and natural history of HIV-related neurologic diseases. Within the context of the Manhattan HIV Brain Bank, we will establish a nationwide resource for the provision of numerous well-characterized brains and tissues for study, and additionally, establish a multi- institutional longitudinal clinical/neurologic and neuropsychiatric database that will serve as a template for following a significant proportion of the medically-serviced, HIV-infected population of New York City, and assist in future studies of HIV neuropathogenesis.